问题描述
我需要在OpenGL中使用Noise(使用Perlin噪声)生成程序地形。每次应用程序运行新地形时,都需要使用新种子生成。 (请勿使用外部库。)制作噪声地形类时是否需要方法/要求。我需要调用什么函数/计算以及顺序?
PS:我使用Visual Studio 2019。
// copy the array data into a float array,and scale and offset the heights.
mHeightmap.resize(NumRows * NumCols,0);
for( int i = 0; i < NumRows * NumCols; ++i)
{
mHeightmap[i] = (float)in[i] * HeightScale;
}
// A height for each vertex
{
std::vector<unsigned char> in(NumRows * NumCols);
// Open the file.
std::ifstream inFile;
inFile.open(heightmapName.c_str(),std::ios_base::binary);
if (inFile)
{
// Read the RAW bytes.
inFile.read((char*)&in[0],(std::streamsize)in.size());
// Done with file.
inFile.close();
}
// copy the array data into a float array,0);
for( int i = 0; i < NumRows * NumCols; ++i)
{
mHeightmap[i] = (float)in[i] * HeightScale;
}
void Terrain::CreateVAO()
{
std::vector<GLfloat> vertices;
vertices.reserve(NumCols * NumRows * 8);
float invTwoDX = 1.0f / (2.0f * CellSpacing);
float invTwoDZ = 1.0f / (2.0f * CellSpacing);
//vertices
for ( int z = 0; z < NumRows; z++)
{
for ( int x = 0; x < NumCols; x++)
{
//vertex data
int i = z * NumCols + x;
vertices.push_back((float)x*CellSpacing);
vertices.push_back(mHeightmap[i]);
vertices.push_back((float)z * CellSpacing);
//normal data
glm::vec3 _N = { 0.0f,1.0f,0.0f };
if(z >= 1 && z < NumRows -1 && x >= 1 && z < NumCols - 1)
{
float t = mHeightmap[(z - 1) * NumCols + x];
float b = mHeightmap[(z + 1) * NumCols + x];
float l = mHeightmap[z * NumCols + x - 1];
float r = mHeightmap[z * NumCols + x + 1];
glm::vec3 tanZ(0.0f,(b - t) * invTwoDZ,1.0f);
glm::vec3 tanX(1.0f,(r - l) * invTwoDX,0.0f);
glm::vec3 _C,_N;
_C = glm::cross(tanZ,tanX);
_N = glm::normalize(_C);
}
vertices.push_back(_N.x);
vertices.push_back(_N.y);
vertices.push_back(_N.z);
vertices.push_back((float)x);
vertices.push_back((float)z);
}
}
std::vector<gluint> indices;
vertices.reserve((NumCols-1)*(NumRows -1)*6);
//indices
for ( int z = 0; z < NumRows-1; z++)
{
for ( int x = 0; x < NumCols-1; x++)
{
GLint a = z * NumCols + x;
GLint b = (z +1) * NumCols + x;
GLint c = z * NumCols + (x+1);
GLint d = (z+1) * NumCols + (x+1);
indices.push_back(c);
indices.push_back(a);
indices.push_back(b);
indices.push_back(c);
indices.push_back(b);
indices.push_back(d);
}
}
indexcount = indices.size();
gluint VBO,EBO;
glGenVertexArrays(1,&VAO);
glBindVertexArray(VAO);
glGenBuffers(1,&EBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,indices.size() * sizeof(gluint),indices.data(),GL_STATIC_DRAW);
glGenBuffers(1,&VBO);
glBindBuffer(GL_ARRAY_BUFFER,VBO);
glBufferData(GL_ARRAY_BUFFER,vertices.size()*sizeof(GLfloat),vertices.data(),GL_STATIC_DRAW);
glVertexAttribPointer(
0,3,GL_FLOAT,GL_FALSE,8 * sizeof(GLfloat),//Strude of the single vertex(pos)
(GLvoid*)0); //Offset from beginning of Vertex
glEnabLevertexAttribArray(0);
glVertexAttribPointer(
1,//Strude of the single vertex(pos+color)
(GLvoid*)(3 * sizeof(GLfloat))); //Offset from beginning of Vertex
glEnabLevertexAttribArray(1);
glVertexAttribPointer(
2,2,//2 float component for coordinates
GL_FLOAT,//Strude of the single vertex(pos+color+texture)
(GLvoid*)(6 * sizeof(GLfloat)));//Offset from beginning of Vertex
glEnabLevertexAttribArray(2);
解决方法
我不确定在您的代码中是否看到Perlin噪声的使用。试试这个轻量级,易于集成的库:
https://github.com/Auburn/FastNoise,其中包含Perlin和大量其他有用的东西,例如可视化工具。
用法很简单
noise.GetNoise((float)x,(float)y);
,您可以将其插入高度功能